Diabetes is a general term for disorders in man having excessive urine excretion as in diabetes mellitus and diabetes insipidus. Diabetes mellitus is a metabolic disorder in which the ability to utilize glucose is more or less completely lost. About 2% of all people suffer from diabetes.
Insulin injections are prescribed to the patients suffering from diabetes. Insulin is a natural hormone, which controls the level of the sugar glucose in the blood. In healthy people, insulin is released in blood by the pancreas as the concentration of blood glucose rises. Increased blood glucose levels, occur after meals and are rapidly compensated by a corresponding increase in insulin secretion. Insulin plays major role in converting the excess blood glucose into glycogen and storing it in liver.
Since the introduction of insulin in the 1920's, continuous strides have been made to improve the treatment of diabetes mellitus. To help avoid extreme glycaemia levels, diabetic patients often practice multiple injection therapy, whereby insulin is administered with each meal.
Insulin is a polypeptide of 51 amino acids, which are divided into 2 amino acid chains: the A chain having 21 amino acids and the B chain having 30 amino acids. The chains are connected to one another by means of two disulfide bridges. Insulin preparations have been employed for diabetes therapy for many years.
Traditionally short acting regular Insulin formulations or its intermediate acting Insulin Protamine formulations were used for treating patients with diabetes mellitus. With time, new insulin analogues and derivatives were developed. Insulin analogues and derivatives differ from human insulin at one or more than one amino acid positions and/or amino acid chain length.
A number of insulin, insulin analogs and derivatives are available in the market. The commonly used types of insulin, insulin analogs or insulin derivatives are categorized as:
Rapid-Acting Insulin Analogs:
For example insulin aspart (Novolog®) or insulin lispro (Humalog®). These analogs begin to work within 5 to 15 minutes of administration and are active for 3 to 4 hours.
Short-Acting Insulin:
For example Regular insulin (Humulin® or Novolin®). Regular insulin starts working within 30 minutes after administration and duration of action lasts from about 5 to 8 hours.
Intermediate-Acting Insulin: For Example as Isophane Insulin. It Starts Working in 1 to 3 hours after administration. Its duration of action varies between 16 to 24 hours.
Long-Acting Insulin:
For example Insulin glargine and Insulin detemir. Both these analogs starts working within 1 to 2 hours and their duration of action varies from about 12 to about 24 hours.
Mixed Insulins:
For example mixture of NPH and regular insulin. There are several variations with different proportions of the mixed insulins. The onset of action of these mixed preparations is about 30 minutes.
Ideally, exogenous insulin is administered at times and in doses that would yield a plasma profile, which mimics the plasma profile of endogenous insulin in a normal individual. Insulin preparations containing analogs of human insulin have shown an absorption profile very close to the normal plasma profile.
The insulin preparations of naturally occurring insulin on the market for insulin substitution differ in the origin of the insulin (e.g. bovine, porcine, human insulin, or another mammalian or animal insulin), and also the composition, whereby the profile of action (onset of action and duration of action) can be influenced. By combination of various insulin preparations, very different profiles of action can be obtained. Preparations of naturally occurring insulins, as well as preparations of insulin derivatives or insulin analogs which show modified kinetics, have been on the market for some time. Recombinant DNA technology today makes possible the preparation of such modified insulins.
These include insulin glargine Gly(A21)-Arg(B31)-Arg(B32)-human insulin with a prolonged duration of action. Insulin glargine is injected as an acidic, clear solution and precipitates on account of its solution properties in the physiological pH range of the subcutaneous tissue as a stable hexamer associate. Insulin glargine is injected once daily and is distinguished compared with other long-acting insulins by its flat serum profile and the reduction of the danger of nightly hypoglycemia associated therewith (Schubert-Zsilavecz et al., 2: 125-130(2001)).
Fast acting insulin(s) are used to control post-prandial increase in the sugar levels. The fast acting insulins include Insulin Lispro, Insulin aspart and Insulin Glulisine. Insulin aspart, AspB28 human insulin, is a fast-acting medication that begins to work very quickly. It is used to treat type 1 (insulin-dependent) diabetes and type 2 (non-insulin-dependent) diabetes. Insulin aspart is usually given together with another long-acting insulin.
Insulin analogs having an accelerated onset of action are described in EP0214826, EP0375437 and EP0678522. EP0124826 relates, inter alia, to substitutions of B27 and B28. EP0678522 describes insulin analogs, which have various amino acids, preferably proline, in position B29, but not glutamic acid.
EP0375437 includes insulin analogs with lysine or arginine in B28, which can optionally additionally be modified in B3 and/or A21. In EP0419504, insulin analogs are disclosed which are protected against chemical modifications, in which asparagine in B3 and at least one further amino acid in the positions A5, A15, A18 or A21 are modified. In WO 92/00321, insulin analogs are described in which at least one amino acid of the positions B1-B6 is replaced by lysine or arginine. According to WO92/00321, insulins of this type have a prolonged action.
In addition to the duration of action, the stability of the preparation is very important for patients. Stabilized insulin formulations having increased physical long-term stability are needed in particular for preparations, which are exposed to particular mechanical stresses or relatively high temperatures. These include, for example, insulins in administration systems such as pens, inhalation systems, needleless injection systems or insulin pumps. Insulin pumps are either worn on or implanted in the body of the patient. In both cases, the preparation is exposed to the heat of the body and movement and to the delivery motion of the pump and thus to a very high thermomechanical stress. Since insulin pens too (disposable and reutilizable pens) are usually worn on the body, the same applies here. Previous preparations have only a limited stability under these conditions.
Insulin is generally present in neutral solution in pharmaceutical concentration in the form of stabilized zinc-containing hexamers, which are composed of 3 identical dimer units (Brange et al., Diabetes Care 13:923-954 (1990)). However, the profile of action an insulin preparation may be improved by reducing the oligomeric state of the insulin it contains. By modification of the amino acid sequence, the self-association of insulin can be decreased. Thus, the insulin analog Lispro, for example, mainly exists as a monomer and is thereby absorbed more rapidly and shows a shorter duration of action (HPT Ammon and C. Werning; Antidiabetika [Antidiabetics]; 2. Ed.; Wiss. Verl.-Ges. Stuttgart; 2000; p. 94.f). However, the rapid-acting insulin analogs, which often exist in the monomeric or dimeric form, are less stable and more prone to aggregate under thermal and mechanical stress than hexameric insulin. This makes itself noticeable in cloudiness and precipitates of insoluble aggregates. (Bakaysa et al, U.S. Pat. No. 5,474,978). These higher molecular weight transformation products (dimers, trimers, polymers) and aggregates decrease not only the dose of insulin administered but can also induce irritation or immune reactions in patients. Moreover, such insoluble aggregates can affect and block the cannulas and tubing of the pumps or needles of pens. Since zinc leads to an additional stabilization of insulin through the formation of zinc-containing hexamers, zinc-free or low-zinc preparations of insulin and insulin analogs are particularly susceptible to instability. In particular, monomeric insulin analogs having a rapid onset of action are prone to aggregate and become physically unstable very rapidly, because the formation of insoluble aggregates proceeds via monomers of insulin.
In order to maintain the quality of an insulin preparation, it is necessary to avoid the formation of aggregates. There are various approaches for stabilizing insulin formulations. Thus, in international patent application WO98/56406, formulations stabilized by TRIS or arginine buffer have been described. U.S. Pat. No. 5,866,538 describes an insulin preparation that contains glycerol and sodium chloride in concentrations of 5-100 Mm and should have an increased stability. U.S. Pat. No. 5,948,751 describes insulin preparations having increased physical stability, which is achieved by addition of mannitol or similar sugars. The addition of excess zinc to a zinc-containing insulin solution can likewise increase the stability (J. Brange et al., Diabetic Medicine, 3: 532-536, 1986). The influence of the pH and various excipients on the stability of insulin preparations has also been described in detail (J. Brange & L. Langkjaer, Acta Pharm. Nordica 4: 149-158).
U.S. Pat. Nos. 7,476,652 and 7,713,930 discloses pharmaceutical formulations that comprise Gly(A21), Arg(B31), Arg(B32)-human insulin; at least one chemical entity chosen from esters and ethers of polyhydric alcohols; at least one preservative; and water, wherein the pharmaceutical formulation has a pH in the acidic range from 1 to 6.8. It has been further disclosed that non-ionic surfactants specifically esters and ethers of polyhydric alcohols (polysorbate 20 and polysorbate 80) increase the stability of acidic insulin preparations and thus preparations can be produced which have superior stability to hydrophobic aggregation nuclei for several months under temperature stress.
It has been also been disclosed in several prior arts that surfactants can causes charge generation in polypeptide solutions and increase the aggregation process and make peptide formulations unstable in long term.
U.S. Pat. No. 5,866,538 discloses a pharmaceutical formulation comprising a polypeptide selected from the group consisting of human insulin, an analogue thereof, a derivative thereof, glycerol, mannitol, or glycerol & mannitol and 5 to 100 mM of a halogenide. It has been shown in the said patent that insulin preparations of superior chemical stability can be obtained in the presence of low halogenide concentrations. Further, Acta Pharmaceutica Nordica 4(4), 1992, pp. 149-158 discloses insulin preparations in which the sodium chloride (Halogenide) concentration has been varied in the range of 0 to 250 mM. However, the major part of the preparations, including all preparations contains a rather high amount of sodium chloride, i.e. 0.7% corresponding approximately to a concentration of 120 mM. It is stated in this document that sodium chloride generally has a stabilizing effect on insulin preparations; glycerol and glucose lead to increased chemical deterioration.
Numbers of attempts have been made till date to provide formulations comprising insulin that remain chemically stable for a sufficiently long period of time.
U.S. Pat. No. 4,476,118 discloses stable insulin solution comprising a preserving agent, an isotonicity agent, and a pH-buffering agent, which solution contains essentially ionized zinc.
U.S. Pat. Nos. 6,906,028 and 6,551,992, 6,034,054 discloses solution formulation comprising: a physiologically tolerated buffer selected from the group consisting of TRIS and arginine; a monomeric insulin analog wherein, the insulin analog is LysB28 ProB29-human insulin; zinc; and a phenolic preservative.
U.S. Pat. No. 6,174,856 discloses that the stability of insulin compositions can be significantly improved by formulating the compositions using a combination of a buffer such as glycylglycine (Gly-Gly) and metal ions such as Ca2+.
U.S. Pat. No. 6,734,162 discloses a method of inhibiting aggregation of a polypeptide comprising combining the polypeptide with a buffer comprising tris(hydroxymethyl) aminomethane (TRIS) mixed with a buffering molecule that does not contain a free amine group and which mitigates the change in pH that results from the formation of carbonic acid; zinc; and a phenolic preservative for a time and under conditions effective to inhibit aggregation.
U.S. Pat. No. 6,737,401 discloses an unexpected property of the novel surfactant stabilized insulin formulations.
U.S. Pat. No. 8,263,551 discloses pharmaceutical formulations comprising insulin, insulin analogs, insulin derivatives or mixtures of the foregoing, and a salt of protamine where the protamine salt wherein protamine salt was used for increasing the physical and chemical stability of an insulin-containing formulation
U.S. Pat. No. 8,097,584 discloses that pharmaceutical polypeptide formulations having increased chemical stability can be obtained by adding ethylenediamine or salts thereof as a buffer to said formulation.
US Patent Application No. 20090175840 discloses an injectable formulation comprising insulin, a diluent suitable for injection, an oxidizing agent or enzyme and a reducing agent or enzyme, with the proviso that the formulation does not contain a chitosan-glycerol phosphate hydrogel.
US Patent Application No. 20090325860 discloses an aqueous pharmaceutical formulation comprising an aqueous mixture of an insulin molecule, a solubilizing agent, a surface active agent, and a thickening agent, wherein the pharmaceutical formulation confers an ultra-rapid acting insulin profile to a non-ultra-rapid acting insulin.
US Patent Application No. 20100069292 discloses a basal insulin formulation comprising a solution of recombinant human insulin at a pH between 3.5 and 4.5, preferably 3.8 to 4.2, or 7.5 to 8.5, optionally in combination with a stabilizing agent, buffering agent and precipitating agent, but not including protamine.
US Patent Application 20120252724 discloses an aqueous pharmaceutical formulation comprising an insulin, insulin analog or insulin derivative, or a pharmacologically tolerable salt thereof, and methionine.
US Patent Application No. 20130011378 discloses a stable co-formulation comprising a therapeutically effective amt. of fast-acting insulin, a hyaluronan-degrading enzyme, NaCl, an antimicrobial preservative, and a stabilizing agents.
US Patent Application No. 20100203014 discloses a method for nasal administration of an acidic pharmaceutical composition to a subject comprising administering to the nasal mucosa of the subject a pharmaceutical composition comprising: i) a therapeutically active peptide; and ii) an aqueous solution buffered with a zwitterionic amino acid, wherein the composition has a pH of about 3.0 to 4.5, thereby administering the acidic pharmaceutical composition to the subject.
US Patent Application No. 20120094903 discloses a pharmaceutical formulation for intranasal delivery of insulin to a patient, comprising an aqueous mixture of human insulin, a solubilizing agent, a surface active agent, and a thickening agent, for nasal delivery.
Chinese Patent Application No. 101045158 discloses a pharmaceutical composition comprising insulin analog, and medical adjuvant containing sugar, organic salt, amino acid, and protein.
IN Patent Application No. 2008MUM01454 discloses an insulin analog protamine crystals comprising human insulin analog, zinc ions, protamine and one or more ligand selected from group consisting of benzyl alcohol, phenylethanol, phenoxyethanol, benzoic acid, mandelic acid, 2,2,2-trifluoro-1-phenylethanol, phenylphosphonic acid and derivatives thereof.
PCT Publication No. 2001000312 discloses systems and methods for manufacturing dry powder formulations.
PCT Publication No. 2012066086 A1 discloses a pharmaceutical formulation comprising insulin glargine and Sulfobutyl Ether 7-[beta]-cyclodextrin.
PCT Publication No. 2007/041481 discloses a formulation comprising intermediate or a long acting insulin, and long acting insulin with an effective amount of a chelator and an acidifying agent to enhance the rate or amount of uptake by a patient.
PCT Publication No. 2010149772 discloses composition comprising an insulin compound or a mixture of two or more insulin compounds, a nicotinic compound and an amino acid.
Several attempts to provide stable insulin, insulin analogs and derivatives formulations have been described previously. However, there still exists a need to develop formulations wherein the insulin does not undergo chemical transformation, and remains stable for a sufficiently long period of time.
Surprisingly, the inventors of present invention found that the insulin preparations having better solubility and chemical stability can be obtained in the presence of solubility-enhancing agent selected from urea, amino acids and/or surfactants with a pH modifying agents other than halogenides.